Liquid-Cooled Portable Computer

1. A portable computer system, comprising: a power source, wherein the power source includes an integrated circuit; a heat pipe having a top surface thermally coupled to the power source and two ends, wherein the heat pipe includes a liquid coolant, and wherein the liquid coolant has a density greater than a first pre-determined value at room temperature; a pump coupled to the heat pipe via a liquid-flow-channel, wherein the pump is configured to circulate the liquid coolant in the heat pipe; and an aluminum plate positioned behind a display of the portable computer system, wherein the pump is further configured to circulate the liquid coolant through or in contact with the aluminum plate via the liquid-flow channel, thereby transferring heat to an environment external to the portable computer system; wherein the liquid coolant completely fills the liquid-flow-channel and includes bubbles of gas.

2. The computer system of claim 1 , wherein the integrated circuit includes a processor.

3. The computer system of claim 1 , wherein the liquid coolant includes water.

4. The computer system of claim 1 , wherein the liquid coolant includes a coolant in an R133 group of coolants.

5. The computer system of claim 1 , wherein the liquid coolant includes a coolant in an R134 group of coolants.

6. The computer system of claim 1 , wherein the first pre-determined value is greater than 100 kg/m3.

7. The computer system of claim 1 , wherein the liquid coolant has a thermal conductivity greater than a second pre-determined value.

8. The computer system of claim 7 , wherein the second pre-determined value is greater than 0.1 W/mK at room temperature.

9. The computer system of claim 1 , wherein the pump includes a mechanical pump.

10. The computer system of claim 1 , wherein the pump includes an electrostatic pump.

11. The computer system of claim 1 , wherein the pump is configured to circulate the liquid coolant using mechanical vibration of a membrane.

12. The computer system of claim 1 , wherein the computer system includes a laptop computer.

13. The computer system of claim 1 , wherein nucleation of the bubbles increases a heat-transfer coefficient of the liquid coolant.

14. The computer system of claim 1 , wherein latent heat is used to increase a heat-transfer coefficient of the liquid coolant.

15. The computer system of claim 1 , wherein the liquid coolant includes metal particles to increase a heat-transfer coefficient of the liquid coolant.

16. The computer system of claim 1 , further comprising a heat exchanger coupled to one of the two ends of the heat pipe, wherein the heat exchanger includes: a forced-fluid driver, wherein the forced-fluid driver is configured to pump heat from inside the computer system to the environment; and a heat coupling-mechanism coupled to the forced-fluid driver.

17. The computer system of claim 16 , wherein the heat coupling-mechanism includes convective-cooling fins.

18. The computer system of claim 1 , further comprising a cold plate coupled to the power source and the heat pipe, wherein the cold plate includes channels which increase a surface area wetted by the liquid coolant, thereby increasing a heat-transfer coefficient of the cold plate.

19. The computer system of claim 18 , wherein a given channel has a width between 10-100 μm.

20. A method for cooling a portable computer system, comprising: circulating a liquid coolant in a heat pipe, wherein the heat pipe has a top surface thermally coupled to an integrated circuit in the portable computer system, and wherein the liquid coolant has a density greater than a first pre-determined value; and circulating the liquid coolant from the heat pipe to an aluminum plate positioned behind a display of the portable computer system via a liquid-flow-channel using a pump, thereby transferring heat to an environment external to the portable computer system, wherein the heat is generated by the integrated circuit in the portable computer system; wherein the liquid coolant completely fills the liquid-flow-channel and includes bubbles of gas.

21. A portable computer system, comprising: an integrated circuit; a heat pipe thermally coupled to the integrated circuit, wherein the heat pipe comprises a cavity containing a liquid coolant, and wherein the liquid coolant absorbs heat produced by the integrated circuit through the thermal coupling; a pump; an aluminum plate coupled behind a display of the portable computer; a liquid flow channel configured in a loop between the heat pipe, the pump, and the aluminum plate; wherein via the liquid flow channel, the pump is configured to circulate the liquid coolant through or in contact with the aluminum plate by: drawing the liquid coolant out of the heat pipe; driving the liquid coolant through or in contact with the aluminum plate and then back into the heat pipe; wherein the liquid coolant completely fills the liquid-flow-channel and includes bubbles of gas.